Process for continuous casting of steel with oil-water mold lubricant



United States Patent Olfice 3,448,787. Patented June 10, 1969 PROCESS FOR CONTINUOUS CASTING OF STEEL WITH OIL-WATER MOLD LUBRICANT Russel L. Beers, Trenton, NJ., assignor to Cities Service Oil Company, Bartlesville, kla., a corporation of Delaware No Drawing. Filed Apr. 30, 1965, Ser. No. 452,353 Int. Cl. B22d 11/10, 11/00 U.S. Cl. 164-73 7 Claims ABSTRACT OF THE DISCLOSURE This invention relates to the continuous casting of metals and more particularly to the use of novel mold lubricants in such casting.

In the art of continuous casting of metals, the bar or ingot being formed moves through, the mold during the casting. An elongated, water cooled mold cavity is normally provided. The mold is usually vertically extending and open at top and bottom. Molten metal poured into the top of the mold moves downwardly as its heat is removed into the sides of the mold and the metal congeals and is removed from the bottom of the mold as a bar or ingot.

It is an object of the present invention to provide improved lubricants for use in continuous casting of metals. Lubricants of the present invention are fire resistant, have excellent heat transfer properties, good spreading properties, low carbon residue and provide a maximum of lubrication with a minimum use of expensive materials.

In accordance with a preferred embodiment of the invention, the interiors of molds used in continuous casting of metals are treated by applying thereto lubricant compositions containing significant quantities of water.

In its broadest form, the invention contemplates the use of any mixture of water with a lubricant material. Depending upon the particular lubricant and relative quantities of water and lubricant employed, the lubricant composition may be in the form of a solution, a mixture or a stable or unstable emulsion. Relative amounts of water and lubricant may vary widely with mixtures containing between about and about 95 wt. percent water and between about 5 and about 95 wt. percent lubricant being preferred.

Suitable lubricant components for use in lubricant compositions of the invention include for instance, animal, vegetable and mineral oils; water soluble, non-oil lubricants, such as polyols, polyoxyalkylene glycols and polyoxyethylene phosphate esters and amine salts thereof as well as non-water soluble, non-oil lubricants.

While a wide variety of lubricants of the various types mentioned above may be used in solution, admixture or emulsion with water, mixtures or emulsions of oil and water are preferred. Because of the fire hazards inherent in continuous casting of metals, especially steel because of the high temperatures involved, oils having a flash point of at least about 400 F. are preferred. To avoid carbon deposition problems, it is preferred that the carbon residue of such oils be not more than 0.5 wt. percent.

In order to provide adequate lubrication and proper spreading under normal casting conditions, lubricant compositions of the present invention preferably have viscosities between about 150 and about 600 Saybolt universal seconds (SUS) at 100 F.

In the case of water insoluble lubricant components, such as oil, emulsifiers may if desired be used to form emulsions. Oil and water emulsions using emulsifiers as desired are preferred lubricant compositions. Emulsifiers for this purpose may be any suitable emulsifiers and may include, for instance, non-ionic, anionic or cationic emulsifiers. Suitable emulsifiers include, sulfonates, sulfates, phosphates, phosphonates, monoglycerides, etc. Nonionic, ashless emulsifiers are preferred for use in forming oil and Water emulsions.

In formulating lubricating compositions of the present invention, other appropriate additives such as corrosion inhibitors, wetting agents, friction modifiers, anti-foam agents, etc. may be used as desired.

While lubricant compositions of the present invention are suitable for lubricating molds of various metals used for casting various metals, they are particularly applicable to processes for the continuous casting of steel. In such processes, copper molds are frequently used.

Lubricating compositions applied to mold surfaces in accordance with the invention may be applied to the mold surface in any suitable manner. U .8. Patents 3,040,- 396 and 2,824,436, for instance described methods of lubricating molds which may be used with lubricating compositions of the present invention.

The following are representative of compositions contemplated by the present invention.

'EXAMPLE 1 Ingredient: Volume percent Cottonseed oil Sorbitan monooleate 2 Water l0 EXAMPLE 2 Ingredient:

Petroleum oil (600 SUS 100 F.) Water 10 EXAMPLE 3 Ingredient:

Prime burning lard oil 9.5 Sodium sulfonate 0.5

Water 90.0

EXAMPLE 4 Ingredient:

Petroleum oil (300 SUS F.) 5.0 Polyoxyethylene sorbitan monooleate 0.4 Water 94.6

EXAMPLE 5 Ingredient: Volume percent Petroleum oil SUS 100 F.) 30 Cottonseed oil 30 Water 40 EXAMPLE 6 Ingredient:

Petroleum oil (450 SUS 100 F.) 85.00 Ditertiary butyl para cresol (antioxident) 0.75 Alkylated succinic anhydride (antirust) 0.05 Silicon antifoam agent (average molecular weight 1200) 0.20 Sperm oil 2.00 Sorbitan monooleate (emulsifier) 2.00 Water 10-00 3 EXAMPLE 7 Ingredient:

Polyoxyalkyleneglycol (molecular weight 20,000) 50.0 Sodium mercaptobenzothiazole 0.5 Laurie acid 1.0 Morpholine (corrosion inhibitor) 1.5 Water 47.0

EXAMPLE 8 Ingredient:

Polyoxyalkyleneglycol (mol. wt. 3,000) 70 Water 3O EXAMPLE 9 Ingredient:

Cramby seed oil 68 Sorbitan monooleate 2 Water 3O EXAMPLE 10 Ingredient:

Castor oil Water 85 EXAMPLE 11 Ingredient:

Tricresylphosphate 30 Water 70 EXAMPLE 12 Ingredient:

Polyoxyethylene phosphate esters (mol. wt.

8,000) 50 Triethanolamine 6 Water 44 EXAMPLE 13 Ingredient:

Mustard oil 60 Borax -Q 3 Water 37 EXAMPLE 14 Analysis of fatty acid portion of glyceride:

Erueic weight percent 59 Linoleic do 8 Linolenic "do--- 7 Eicosenoic do 4 Palmitic do 2 Decosanoic do 1.5

Others do 18.5

Iodine value 91 Free fatty acids -weight percent 0.4 Unsaponifiables do 1 Density at 25 C. gram/cm 939 Flash point (Cleveland open cup) degree F 650 Fire point "degree F 685 Viscosity SUS 100 F 230 Carbon residue (Ramsbottorn) weight percent.- 0.16

While the invention has been described above with respect to certain preferred embodiments thereof, it should be understood that various changes and modifications may be made without departing from the spirit and scope of the invention and it is intended to cover all such modifications and changes in the appended claims.

I claim:

1. A process for treating an interior surface of a mold used in continuous casting of steel which comprises applying to such surface during such casting a lubricant composition comprising between about 5 and about wt. percent oil and between about 5 and about 95 wt. percent water.

2. The process of claim 1 in which the lubricant composition when applied to the mold surface is in the form of an oil and water emulsion.

3. The process of claim 2 in which the oil has a flash point of at least 400 and the lubricant composition has a viscosity between about 150 and about 600 SUS F.

4. The process of claim 3 in which the oil is a petroleum oil.

5. The process of claim 3 in which the oil is a vegetable oil.

6. The process of claim 3 in which the lubricant composition includes between about 0.1 and about 5 wt. percent of an emulsifying agent.

7. A process for continuous cast molding of steel which comprises admitting molten steel to be cast into the top of an open bottom mold, applying to at least a portion of the interior surface of said mold a lubricant composition comprising an oil and water emulsion containing between about 5 and about 95 wt. percent of water and between about 5 and about 95 wt. percent of oil and causing the metal to emerge from the bottom of the mold as a formed ingot in a continuous operation.

References Cited UNITED STATES PATENTS 2,595,928 5/1952 Currie et al. 252-358 2,829,112 4/1958 Solomon 252-358 3,034,186 5/ 1962 Holshouser 164-73 3,052,936 9/1962 Hamilton 164-56 3,220,070 11/ 1965 Tajkowski 164-73 J. SPENCER OVERHOLSER, Primary Examiner.

R. D. BALDWIN, Assistant Examiner. 

